102 ANATIDE. 



Of those produced at tlic Gardens of the Zoological So- 

 ciety, the young birds in the middle of last August, when 

 about ten weeks old, the beak was of a dull flesh colour, the 

 tip and lateral margins black ; the head, neck, and all the 

 upper surface of the body pale ash brown ; the under surface 

 before the legs of a paler brown ; the portion behind the legs 

 dull white ; the legs, like the beak, of a dingy flesh colour. 



The same young birds, in the middle of October, have the 

 beak black at the end ; a reddish orange band across the 

 nostrils, the base and lore pale greenish-white ; the general 

 colour pale greyish-brown ; a few of the smaller wing-coverts 

 white, mixed with others of a pale bufFy brown ; the legs 

 black. 



The young Hoopers bred in 1839, had lost almost all 

 their brown feathers at the autumn moult of 1840, and before 

 their second winter was over they were entirely white ; the 

 base of the beak lemon yellow. 



The internal distinctions of the Hooper are more con- 

 spicuous than those which have been referred to as external, 

 and of the former, the organ of voice furnishes the most 

 valuable and decisive characters. This peculiarity was known 

 to Willughby, but it was previously noticed by Sir Thomas 

 Browne, who mentions " that strange recurvation of the wind- 

 pipe through the sternum.*" 



The cylindrical tube of the trachea or windpipe passes 

 down the whole length of the long neck of the bird, in the 

 usual manner, but descends between the two branches of the 

 forked bone, called the merrythought, to a level with the keel 

 of the breast-bone or sternum. The keel of the breast-bone 

 is double, and receives between its two plates or sides, the 

 tube of the trachea, which, after traversing nearly the whole 

 length of the keel, turns suddenly upon itself, passing for- 

 wards, upwards, and again backwards, till it ends in the ver- 

 tical bone of divarication, from whence the two long branchial 



